Integrated crop pollination to buffer spatial and temporal variability in pollinator activity

Insect pollination improves the yield and quality of many crops, yet there is increasing evidence of insufficient insect pollinators limiting crop production. Effective Integrated Crop Pollination (ICP) involves adaptable, targeted and cost effective management of crop pollination and encourages the use of both wild and managed pollinators where appropriate. In this study we investigate how the addition of honeybee hives affects the community of insects visiting oilseed rape, and if hive number and location affect pollinator foraging and oilseed rape pollination in order to provide evidence for effective ICP. We found that introducing hives increased overall flower visitor numbers and altered the pollinator community, which became dominated by honeybees. Furthermore a greater number of hives did not increase bee numbers significantly but did result in honeybees foraging further into fields. The timing of surveys and proximity to the field edge influenced different pollinators in different ways and represents an example of spatial and temporal complementarity. For example dipteran flower visitor numbers declined away from the field edge whereas honeybees peaked at intermediate distances into the field. Furthermore, no significant effects of survey round on wild bees overall was observed but honeybee numbers were relatively lower during peak flowering and dipteran abundance was greater in later survey rounds. Thus combining diverse wild pollinators and managed species for crop pollination buffers spatial and temporal variation in flower visitation. However we found no effect of insect pollination on seed set or yield of oilseed rape in our trial, highlighting the critical need to understand crop demand for insect pollination before investments are made in managing pollination services

A critical analysis of the potential for EU Common Agricultural Policy measures to support wild pollinators on farmland

1. Agricultural intensification and associated loss of high‐quality habitats are key drivers of insect pollinator declines. With the aim of decreasing the environmental impact of agriculture, the 2014 EU Common Agricultural Policy (CAP) defined a set of habitat and landscape features (Ecological Focus Areas: EFAs) farmers could select from as a requirement to receive basic farm payments. To inform the post‐2020 CAP, we performed a European‐scale evaluation to determine how different EFA options vary in their potential to support insect pollinators under standard and pollinator‐friendly management, as well as the extent of farmer uptake. 2. A structured Delphi elicitation process engaged 22 experts from 18 European countries to evaluate EFAs options. By considering life cycle requirements of key pollinating taxa (i.e. bumble bees, solitary bees and hoverflies), each option was evaluated for its potential to provide forage, bee nesting sites and hoverfly larval resources. 3. EFA options varied substantially in the resources they were perceived to provide and their effectiveness varied geographically and temporally. For example, field margins provide relatively good forage throughout the season in Southern and Eastern Europe but lacked early‐season forage in Northern and Western Europe. Under standard management, no single EFA option achieved high scores across resource categories and a scarcity of late season forage was perceived. 4. Experts identified substantial opportunities to improve habitat quality by adopting pollinator‐friendly management. Improving management alone was, however, unlikely to ensure that all pollinator resource requirements were met. Our analyses suggest that a combination of poor management, differences in the inherent pollinator habitat quality and uptake bias towards catch crops and nitrogen‐fixing crops severely limit the potential of EFAs to support pollinators in European agricultural landscapes. 5. Policy Implications. To conserve pollinators and help protect pollination services, our expert elicitation highlights the need to create a variety of interconnected, well‐managed habitats that complement each other in the resources they offer. To achieve this the Common Agricultural Policy post‐2020 should take a holistic view to implementation that integrates the different delivery vehicles aimed at protecting biodiversity (e.g. enhanced conditionality, eco‐schemes and agri‐environment and climate measures). To improve habitat quality we recommend an effective monitoring framework with target‐orientated indicators and to facilitate the spatial targeting of options collaboration between land managers should be incentivised

Assessment of the response of pollinator abundance to environmental pressures using structured expert elicitation

Policy-makers often need to rely on experts with disparate fields of expertise when making policy choices in complex, multi-faceted, dynamic environments such as those dealing with ecosystem services. For policy-makers wishing to make evidence-based decisions which will best support pollinator abundance and pollination services, one of the problems faced is how to access the information and evidence they need, and how to combine it to formulate and evaluate candidate policies. This is even more complex when multiple factors provide influence in combination. The pressures affecting the survival and pollination capabilities of honey bees (Apis mellifera), wild bees, and other pollinators are well documented, but incomplete. In order to estimate the potential effectiveness of various candidate policy choices, there is an urgent need to quantify the effect of various combinations of factors on the pollination ecosystem service. Using high-quality experimental evidence is the most robust approach, but key aspects of the system may not be amenable to experimentation or may be prohibitive based on cost, time and effort. In such cases, it is possible to obtain the required evidence by using structured expert elicitation, a method for quantitatively characterizing the state of knowledge about an uncertain quantity. Here we report and discuss the outputs of the novel use of a structured expert elicitation, designed to quantify the probability of good pollinator abundance given a variety of weather, disease, and habitat scenarios

Protecting an ecosystem service: approaches to understanding and mitigating threats to wild insect pollinators

Insect pollination constitutes an ecosystem service of global importance, providing significant economic and aesthetic benefits as well as cultural value to human society, alongside vital ecological processes in terrestrial ecosystems. It is therefore important to understand how insect pollinator populations and communities respond to rapidly changing environments if we are to maintain healthy and effective pollinator services. This paper considers the importance of conserving pollinator diversity to maintain a suite of functional traits to provide a diverse set of pollinator services. We explore how we can better understand and mitigate the factors that threaten insect pollinator richness, placing our discussion within the context of populations in predominantly agricultural landscapes in addition to urban environments. We highlight a selection of important evidence gaps, with a number of complementary research steps that can be taken to better understand: i) the stability of pollinator communities in different landscapes in order to provide diverse pollinator services; ii) how we can study the drivers of population change to mitigate the effects and support stable sources of pollinator services; and, iii) how we can manage habitats in complex landscapes to support insect pollinators and provide sustainable pollinator services for the future. We advocate a collaborative effort to gain higher quality abundance data to understand the stability of pollinator populations and predict future trends. In addition, for effective mitigation strategies to be adopted, researchers need to conduct rigorous field-testing of outcomes under different landscape settings, acknowledge the needs of end-users when developing research proposals and consider effective methods of knowledge transfer to ensure effective uptake of actions

Emerging threats and opportunities to managed bee species in European agricultural systems: a horizon scan

Managed bee species provide essential pollination services that contribute to food security worldwide. However, managed bees face a diverse array of threats and anticipating these, and potential opportunities to reduce risks, is essential for the sustainable management of pollination services. We conducted a horizon scanning exercise with 20 experts from across Europe to identify emerging threats and opportunities for managed bees in European agricultural systems. An initial 63 issues were identified, and this was shortlisted to 21 issues through the Horizon Scanning process. These ranged from local landscape-level management to geopolitical issues on a continental and global scale across seven broad themes - Pesticides & pollutants, Technology, Management practices, Predators & parasites, Environmental stressors, Crop modification, and Political & trade influences. While we conducted this Horizon Scan within a European context, the opportunities and threats identified will likely be relevant to other regions. A renewed research and policy focus, especially on the highest-ranking issues, is required to maximise the value of these opportunities and mitigate threats to maintain sustainable and healthy managed bee pollinators within agricultural systems

Design and planning of a transdisciplinary investigation into farmland pollinators: rationale, co-design, and lessons learned

To provide a complete portrayal of the multiple factors negatively impacting insects in agricultural landscapes it is necessary to assess the concurrent incidence, magnitude, and interactions among multiple stressors over substantial biogeographical scales. Trans-national ecological field investigations with wide-ranging stakeholders typically encounter numerous challenges during the design planning stages, not least that the scientific soundness of a spatially replicated study design must account for the substantial geographic and climatic variation among distant sites. ‘PoshBee’ (Pan-European assessment, monitoring, and mitigation of Stressors on the Health of Bees) is a multi-partner transdisciplinary agroecological project established to investigate the suite of stressors typically encountered by pollinating insects in European agricultural landscapes. To do this, PoshBee established a network of 128 study sites across eight European countries and collected over 50 measurements and samples relating to the nutritional, toxicological, pathogenic, and landscape components of the bees’ environment. This paper describes the development process, rationale, and end-result of each aspect of the of the PoshBee field investigation. We describe the main issues and challenges encountered during the design stages and highlight a number of actions or processes that may benefit other multi-partner research consortia planning similar large-scale studies. It was soon identified that in a multi-component study design process, the development of interaction and communication networks involving all collaborators and stakeholders requires considerable time and resources. It was also necessary at each planning stage to be mindful of the needs and objectives of all stakeholders and partners, and further challenges inevitably arose when practical limitations, such as time restrictions and labour constraints, were superimposed upon prototype study designs. To promote clarity for all stakeholders, for each sub-component of the study, there should be a clear record of the rationale and reasoning that outlines how the final design transpired, what compromises were made, and how the requirements of different stakeholders were accomplished. Ultimately, multi-national agroecological field studies such as PoshBee benefit greatly from the involvement of diverse stakeholders and partners, ranging from field ecologists, project managers, policy legislators, mathematical modelers, and farmer organisations. While the execution of the study highlighted the advantages and benefits of large-scale transdisciplinary projects, the long planning period emphasized the need to formally describe a design framework that could facilitate the design process of future multi-partner collaborations

Raman Gas Species Measurements in Hydrocarbon-Fueled Rocket Engine Injector Flows

Rocket engine propellent injector development at NASA-Marshall includes experimental analysis using optical techniques, such as Raman, fluorescence, or Mie scattering. For the application of spontaneous Raman scattering to hydrocarbon-fueled flows a technique needs to be developed to remove the interfering polycyclic aromatic hydrocarbon fluorescence from the relatively weak Raman signals. A current application of such a technique is to the analysis of the mixing and combustion performance of multijet, impinging-jet candidate fuel injectors for the baseline Mars ascent engine, which will burn methane and liquid oxygen produced in-situ on Mars to reduce the propellent mass transported to Mars for future manned Mars missions. The Raman technique takes advantage of the strongly polarized nature of Raman scattering. It is shown to be discernable from unpolarized fluorescence interference by subtracting one polarized image from another. Both of these polarized images are obtained from a single laser pulse by using a polarization-separating calcite rhomb mounted in the imaging spectrograph. A demonstration in a propane-air flame is presented, as well as a high pressure demonstration in the NASA-Marshall Modular Combustion Test Artice, using the liquid methane-liquid oxygen propellant syste

Insect pollinators: linking research and policy. Workshop report.

EXECUTIVE SUMMARY Pollinators interact with plants to underpin wider biodiversity, ecosystem function, ecosystem services to agricultural crops and ultimately human nutrition. The conservation of pollinators is thus an important goal. Pollinators and pollination represent a tractable example of how biodiversity can be linked to an ecosystem service. This represents a case study for exploring the impacts of various policy instruments aiming to halt/reverse the loss of ecosystem services. There is a need to understand how multiple pressures (e.g. habitat loss, fragmentation and degradation, climate change, pests and diseases, invasive species and environmental chemicals) can combine or interact to affect diversity, abundance and health of different pollinator groups. Decision makers need to balance consideration of the effects of single pressures on pollinators against the suite of other pressures on pollinators. For instance, the threat from pesticide use (with its high public and media profile) also needs to be considered in the context of the other threats facing pollinators and balanced against the need for food security. An independent review of the balance of risks across pollinator groups from pesticide use would help synthesise current knowledge into an accessible form for decision makers. To manage or lessen these threats to pollinators (wild and managed) and pollination requires improved knowledge about their basic ecology. We still need to know where and in what numbers different pollinator species occur, how they use different environments, how they interact with each other through shared plants and diseases and how wild pollinator abundance is changing. Decision makers need clear factual evidence for i) the relative contribution of different managed and wild pollinator groups to wildflower and crop pollination and ii) how this varies across different land-uses, ecosystems and regions. Addressing these basic and applied questions will improve our ability to forecast impacts on pollination service delivery to agricultural crops arising from current and future environmental changes, pesticide use and emerging diseases. The development of a long-term, multi-scale monitoring scheme to monitor trends in pollinator (wild and managed) population size and delivery of pollination services (ideally tied to data collection on land-use, pesticide applications and disease incidence at relevant spatial scales) would provide the evidence base for developing the effectiveness of policy and management interventions over time. Such a monitoring scheme would benefit from including research council organisations (e.g. CEH), governmental departments (e.g. Fera), universities, museums and NGOs (e.g. BBKA,SBA, Bumblebee Conservation Trust etc) Insect Pollinators: linking research and policy Workshop Report | 5 In the context of agricultural intensification and conservation we need to establish what type, quality and quantity of interventions (e.g. agri-environment schemes, protected areas) are needed, where to place them and how they can sustain different pollinator populations and effective pollination services. Current monitoring of the risks from diseases and pesticides requires broadening to consider other insects aside from honey bees, unless we can demonstrate that honey bees are good surrogates for all other pollinators. There is a need to increase confidence in regulatory risk assessments pertaining to pathogens and pesticides by incorporating other pollinator species, investigating chronic exposure to multiple chemicals and using field relevant dosages (specific to regions, not using other data sources as surrogates). At present the effects of spatial, social and temporal scales on the benefits stakeholders receive from pollination services are only beginning to be understood. Economic valuation of pollination services can help optimise the cost-effectiveness of service management measures and offer new opportunities to incentivise action or raise awareness among stakeholders. Novel tools and instruments (e.g. education and training) are needed to translate broad international (e.g. CBD, EU Biodiversity Strategy) and national (e.g. England‟s Biodiversity Strategy) policies into local actor (e.g. beekeeper, farmer, citizen scientist) contributions to meet biodiversity commitments Refocusing some public funding to link basic science to development of practical solutions (e.g. better crop protection products, improved disease resistance or treatment) could help science deliver better-targeted evidence for pollinator protection. Scientists need to make more use of opportunities (e.g. POSTnotes1; practitioner guides) to transfer knowledge to a broad audience in order to better influence decision maker and practitioner behaviours. Improved knowledge exchange between scientists and decision makers is important to combating threats to pollination. Central to this is improved understanding of the respective positions of policy makers and scientists. For instance, policy-makers usually need to be presented with a range of options to balance against other areas of policy. Science does not always arrive at a consensus due to uncertainties in data or models. Policy-makers need to understand that scientists are communicating the “best available knowledge at present” and that consequently it is not always possible to give a definitive answer